The colour of old brown sherry

Madge Bettany was good to look at. She was slight to the verge of thinness, with a well-poised head covered by a mop of curly dark brown hair.  Her eyes were dark brown too - the colour of old brown sherry - and were shaded by long, upcurling, black lashes.

E.M. Brent-Dyer, The school at the chalet (1925), 5

Amazingly, this description is on the very first page of the entire sequence of chalet school stories. I am heartened to think that teenage girls of the 1920s would have been expected to know what old sherry looked like.